Modular gun system

Abstract

A method and apparatus for coupling a pre-wired end fitting with a shaped charge loading tube where the end fitting centers and orients the loading tube within a perforating gun and further includes a selective switch, feed through contact and orifices to insert a wireless detonator and detonating cord, the loading tube being pre-wired with insulated wire.

What is claimed is: 
     
       1. A perforating gun system comprising:
 a cylindrical housing with a bottom end and a top end; 
 a prewired loading tube assembly disposed within the cylindrical housing and having a corresponding bottom end and top end; 
 an upper end fitting coupled to the top end of the prewired loading tube and the top end of the cylindrical housing; 
 a lower end fitting coupled to the bottom end of the prewired loading tube and the bottom end of the cylindrical housing; 
 upper electrical connections coupled to the upper end fitting; 
 lower electrical connections coupled to the bottom end fitting; 
 a selective switch coupled to a detonator connector receptacle disposed within the upper end fitting; 
 a detonator electrically coupled to the selective switch and further disposed within the upped end fitting; 
 wherein the detonator has an auto-shunting feature that does not un-shunt until a mating receptacle is inserted; and 
 wherein the selective switch has a ribbon pigtail with the un-shunting receptacle attached. 
 
     
     
       2. The prewired loading tube assembly of  claim 1 , wherein the upper end fitting disposed within the pre-wired loading tube houses a selective switch wherein the upper end fitting contains a portion to receive an auto-shunting modular detonator by electrically connecting it to a mating receptacle of the upper end fitting selective switch and affixing the auto-shunting modular detonator proximate to a detonating cord. 
     
     
       3. The perforating gun system of  claim 1 , further comprising a means for auto-shunting the detonator. 
     
     
       4. The perforating gun system of  claim 1 , further including coupling a baffle to the bottom end of the cylindrical housing. 
     
     
       5. The perforating gun system of  claim 1 , wherein the prewired loading tube further comprises an insulated wire which is terminated at the selective switch in the upper end and a pressure bulkhead coupled to the lower end. 
     
     
       6. The perforating gun system of  claim 1 , wherein the selective switch is grounded to the loading tube. 
     
     
       7. The perforating gun system of  claim 6 , wherein the loading tube is electrically connected to a baffle. 
     
     
       8. The perforating gun system of  claim 1 , further including shaped charges installed into the loading tube, wherein the shaped charges are held in place by a locking means fixed to the shaped charge. 
     
     
       9. The perforating gun system of  claim 8 , further comprising a detonating cord coupled to the back of the shaped charges with a detonating cord locking means. 
     
     
       10. The perforating gun system of  claim 9 , wherein the detonating cord terminates into a detonating cord orifice integral with the upper end fitting or the lower end fitting. 
     
     
       11. The perforating gun system of  claim 10 , wherein the detonator is located adjacent to the detonating cord in an end-to-end configuration. 
     
     
       12. The perforating gun system of  claim 1 , wherein the receptacle connected to the switch is attached to the end of the detonator, disengaging the shunt of the detonator. 
     
     
       13. A pre-wired shaped charge loading tube assembly comprising:
 a cylindrical housing with a bottom end and a top end; 
 an upper end fitting coupled to a top end of the prewired loading tube and the top end of the cylindrical housing; 
 a lower end fitting coupled to a bottom end of the prewired loading tube and the bottom end of the cylindrical housing; 
 upper electrical connections coupled to the upper end fitting; 
 lower electrical connections coupled to the bottom end fitting; 
 a selective switch coupled to a detonator connector receptacle disposed within the upper end fitting; and 
 a detonator electrically coupled to the selective switch and further disposed within the upped end fitting, wherein the detonator has an auto-shunting feature that does not un-shunt until a mating receptacle is inserted. 
 
     
     
       14. The pre-wired shaped charge loading tube assembly of  claim 13 , wherein the upper end fitting disposed within the pre-wired loading tube houses a selective switch wherein the upper end fitting contains a portion to receive an auto-shunting modular detonator by electrically connecting it to a mating receptacle of the upper end fitting selective switch and affixing the auto-shunting modular detonator proximate to a detonating cord. 
     
     
       15. The pre-wired shaped charge loading tube assembly of  claim 13 , further comprising a means for auto-shunting the detonator. 
     
     
       16. The pre-wired shaped charge loading tube assembly of  claim 13 , further including coupling a baffle to the bottom end of the cylindrical housing. 
     
     
       17. The pre-wired shaped charge loading tube assembly of  claim 13 , wherein the prewired loading tube further comprises an insulated wire which is terminated at the selective switch in the upper end and a pressure bulkhead coupled to the lower end. 
     
     
       18. The pre-wired shaped charge loading tube assembly of  claim 13 , wherein the selective switch is grounded to the loading tube. 
     
     
       19. The pre-wired shaped charge loading tube assembly of  claim 18 , wherein the loading tube is electrically connected to a baffle. 
     
     
       20. The pre-wired shaped charge loading tube assembly of  claim 13 , further including shaped charges installed into the loading tube, wherein the shaped charges are held in place by a locking means fixed to the shaped charge. 
     
     
       21. The pre-wired shaped charge loading tube assembly of  claim 20 , further comprising a detonating cord coupled to the back of the shaped charges with a detonating cord locking means. 
     
     
       22. The pre-wired shaped charge loading tube assembly of  claim 21 , wherein the detonating cord terminates into a detonating cord orifice integral with the upper end fitting or the lower end fitting. 
     
     
       23. The pre-wired shaped charge loading tube assembly of  claim 22 , wherein the detonator is located adjacent to the detonating cord in an end-to-end configuration. 
     
     
       24. The pre-wired shaped charge loading tube assembly of  claim 13 , wherein the selective switch has a ribbon pigtail with the un-shunting receptacle attached. 
     
     
       25. The pre-wired shaped charge loading tube assembly of  claim 24 , wherein the receptacle connected to the switch is attached to the end of the detonator, disengaging the shunt of the detonator.